Fast response color waveforms for multiparticle electrophoretic displays
Fast response color waveforms for driving multi-particle color electrophoretic media to improve the user experience of a display, e.g. a tablet, monitor, or interactive sign, that incorporates multi-particle color electrophoretic media. In particular, the waveforms result in a sharp and immediate response, which is preferred when writing with a stylus, or typing on a keyboard, or interacting with an icon on a sign, such as a timetable.
1 . A method of causing a color state transition in a four-particle electrophoretic display comprising one negative particle set and three different positive particle sets, wherein each particle set is a different color and one of the particle sets is white in color, and wherein the display is configured to provide at least five voltages to pixel electrodes of the display, V++, V+, 0, V−, and V−−, the method comprising:
providing a first sequence including at least three sequential frames of a same polarity (+ or −), wherein a first frame of the first sequence is at a respective highest voltage (V++, V−−);
providing a second sequence including at least three sequential frames of an opposite polarity (− or +); and
providing a third sequence including at least one frame of the same polarity (+ or −) or zero volts.
2 . The method of claim 1 , wherein the first sequence includes frames at V++ and V+, or at V−− and V−.
3 . The method of claim 1 , wherein the second sequence includes frames at V−− and V−, or at V++ and V+.
4 . The method of claim 1 , wherein the display is further configured to provide an additional positive voltage between V++ and 0 and an additional negative voltage between V−− and 0, and the first sequence includes frames at the additional positive voltage between V++ and 0 or at the additional negative voltage between V−− and 0.
5 . The method of claim 4 , wherein the voltages are V++=24V, V+=6V, 0V, V−=−6V, and V−−=−24V, and the additional positive voltage between V++ and 0 is +12V, and the additional negative voltage between V−− and 0 is −12V.
6 . The method of claim 1 , wherein the display is further configured to provide an additional positive voltage between V++ and 0 and an additional negative voltage between V−− and 0, and the second sequence includes frames at the additional negative voltage between V−− and 0 or at the additional positive voltage between V++ and 0.
7 . The method of claim 6 , wherein the voltages are V++=24V, V+=6V, 0V, V−=−6V, and V−−=−24V, and the additional positive voltage between V++ and 0 is +12V, and the additional negative voltage between V−− and 0 is −12V.
8 . The method of claim 1 , wherein an elapsed time for transition from a white state to a final color at the viewing surface is less than 300 ms or less than 250 ms.
9 . The method of claim 1 , wherein each frame is less than 20 ms in time.
10 . A method of causing a color state transition in a four-particle electrophoretic display comprising one positive particle set and three different negative particle sets, wherein each particle set is a different color and one of the particle sets is white in color, and wherein the display is configured to provide at least five voltages to pixel electrodes of the display, V++, V+, 0, V−, and V−−, the method comprising:
providing a first sequence including at least three sequential frames of a same polarity (+ or −), wherein a first frame of the first sequence is at a respective highest voltage (V++, V−−);
providing a second sequence including at least three sequential frames of an opposite polarity (− or +); and
providing a third sequence including at least one frame of the same polarity (+ or −) or zero volts.
11 . The method of claim 10 , wherein the first sequence includes frames at V++ and V+, or at V−− and V−.
12 . The method of claim 10 , wherein the second sequence includes frames at V−− and V−, or at V++ and V+.
13 . The method of claim 10 , wherein the display is further configured to provide an additional positive voltage between V++ and 0 and an additional negative voltage between V−− and 0, and the first sequence includes frames at the additional positive voltage between V++ and 0 or at the additional negative voltage between V−− and 0.
14 . The method of claim 13 , wherein the voltages are V++=24V, V+=6V, 0V, V−=−6V, and V−−=−24V, and the additional positive voltage between V++ and 0 is +12V, and the additional negative voltage between V−− and 0 is −12V.
15 . The method of claim 10 , wherein the display is further configured to provide an additional positive voltage between V++ and 0 and an additional negative voltage between V−− and 0, and the second sequence includes frames at the additional negative voltage between V−− and 0 or at the additional positive voltage between V++ and 0.
16 . The method of claim 15 , wherein the voltages are V++=24V, V+=6V, 0V, V−=−6V, and V−−=−24V, and the additional positive voltage between V++ and 0 is +12V, and the additional negative voltage between V−− and 0 is −12V.
17 . The method of claim 10 , wherein an elapsed time for transition from a white state to a final color at the viewing surface is less than 300 ms or less than 250 ms.
18 . The method of claim 10 , wherein each frame is less than 20 ms in time.
19 . A method of causing a color state transition in a four-particle electrophoretic display comprising two negative particle sets and two different positive particle sets, wherein each particle set is a different color and one of the particle sets is white in color, and wherein the display is configured to provide at least five voltages to pixel electrodes of the display, V++, V+, 0, V−, and V−−, the method comprising:
providing a first sequence including at least three sequential frames of a same polarity (+ or −), wherein a first frame of the first sequence is at a respective highest voltage (V++, V−−);
providing a second sequence including at least three sequential frames of an opposite polarity (− or +); and
providing a third sequence including at least one frame of the same polarity (+ or −) or zero volts.